题意:给定一个正整数数组,求最长的区间,使得该区间内存在一个元素,它能整除该区间的每个元素. 析:暴力每一个可能的区间,从数组的第一个元素开始考虑,向两边延伸,设延伸到的最左边的点为l, 最右边的点为r.那么我们下一点考虑r+1即可, 因为[l, r]之间不会有更优解. 代码如下: #pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string>…

原题 RMQ st表棵题 要想让一个区间里的所有数都可以整除其中一个数,那么他一定是这个区间内的最小值,并且同时是这个区间的gcd.然后这个问题就转化成了RMQ问题. 维护两个st表,分别是最小值和gcd,然后二分最长区间长度,用st表check即可. #include<cstdio> #include<algorithm> #include<cmath> #define N 300010 using namespace std; int n,a[N],mn[N][20…

题面: 给一个序列,求最长的合法区间,合法被定义为这个序列的gcd=区间最小值 输出最长合法区间个数,r-l长度 接下来输出每个合法区间的左端点 题解: 由于区间gcd满足单调性,所以我们可以二分区间长度,用st表维护区间最小值和gcd即可 #include<cstdio> #include<algorithm> #include<cstring> #include<cmath> #define N 300100 using namespace std; i…

D. Pair of Numbers time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Simon has an array a1, a2, ..., an, consisting of n positive integers. Today Simon asked you to find a pair of integers l…

D. Pair of Numbers time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Simon has an array a1, a2, ..., an, consisting of n positive integers. Today Simon asked you to find a pair of integers l…

[codeforces 55]D. Beautiful numbers 试题描述 Volodya is an odd boy and his taste is strange as well. It seems to him that a positive integer number is beautiful if and only if it is divisible by each of its nonzero digits. We will not argue with this and…

题目链接: http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=47319 题目大意:给定一个序列,要求确定一个子序列,①使得该子序列中所有值都能被其中一个值整除,②且子序列范围尽可能大(r-l尽可能大). 解题思路: 对于要求1,不难发现只有min(L,R)=gcd(L,R)时才行.其中gcd是L,R范围内的最大公约数,min是L,R范围内的最小值. 对于要求2,传统思路是r-l从大到小枚举,每次确定一个(L,R)范围,进行判…

Simon has an array a1, a2, ..., an, consisting of n positive integers. Today Simon asked you to find a pair of integers l, r (1 ≤ l ≤ r ≤ n), such that the following conditions hold: there is integer j (l ≤ j ≤ r), such that all integers al, al + 1, …

Magic Numbers 题意: 题意比较难读:首先对于一个串来说, 如果他是d-串, 那么他的第偶数个字符都是是d,第奇数个字符都不是d. 然后求[L, R]里面的多少个数是d-串,且是m的倍数. 题解: 数位dp. dp[x][y]代表的是余数为x, 然后剩下的长度是y的情况的方案数是多少. 代码: #include<bits/stdc++.h> using namespace std; #define Fopen freopen("_in.txt","r&…

Codeforces Round #597 (Div. 2 Consider the set of all nonnegative integers: 0,1,2,-. Given two integers a and b (1≤a,b≤104). We paint all the numbers in increasing number first we paint 0, then we paint 1, then 2 and so on. Each number is painted whi…